Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Pension Benefits
Components of expense/ (income) related to net benefit expense:
Service Cost	$ 12	$ 11	$ 34	$ 33
Interest Cost	29	30	87	92
Expected Return on Plan Assets	(41)	(41)	(122)	(124)
Amortization of Net Loss	17	15	52	43
Net Periodic Benefit Cost	17	15	51	44
Special Termination Employee Benefits	0	0	7	0
Total Expense	17	15	58	44
Other Post-retirement Benefits
Components of expense/ (income) related to net benefit expense:
Service Cost	2	1	3	2
Interest Cost	3	4	10	11
Amortization of Net Loss	1	1	3	4
Amortization of Prior Service Costs	(1)	0	(1)	(1)
Total Expense	$ 5	$ 6	$ 15	$ 16